Paper 2 - required practicals

Question 1

Write a method for calculating the density of a regularly shaped object.

Answer 1

1. Measure the length, width and height of the object using appropriate measuring equiptment. And record dimensions.
2. Calculate the volume using lenght x width x height
3. Measure the mass using a balance and record.
4. Calculate the density using the formula density = mass/volume
5. Repeat for two more regular objects and find the mean average

Question 2

Write a method for calculating the density of a liquid

Answer 2

1. Measure the mass of empty measuring cylinder.
2. Fill measuring cylinder to 50cm and record exact volume.
3. Measure the mass of the cylinder and liquid.
4. Calculate the mass by finding the difference between the two measurements
5. Calculate the density using the formula : density = mass/volume

Question 3

Write a method for investigating force and extension

Answer 3

1. Set up equipment with no masses or the mass holder on the spring
2. Measure the length of the spring with no mass attached. Record this information.
3. Add a mass to end of the spring and measure the new length.
4. Record the force on the spring. Calculate how much the spring has extended by the difference between two lengths
5. Repeat steps 3 and 4 adding the same amount of masses each time.
6. Stop when spring shows signs of reaching its limit of proportionality
7. Plot a graph using results.

Question 4

Write a method for an acceleration practical using light gates.

Answer 4

1. Set up the equipment
2. Measure the width of each segment of the interrupt car and enter values into datalogger.
3. Place 400g of mass on the trolley and 100g of mass onto the hook. Then hold the trolley in place at designated start line.
4. Record the acceleration of the trolley as it passes through the light gate using datalogger and record results in a table.
5. Repeat twice more, record results and calculate mean average.
6. Take 100g of the trolley and add to the hook. Then measure the acceleration for this force
7. Repeat step 4 up to 5N so all weights are on the hook and none on the trolley.

Question 5

Write a method for an acceleration practical using stopwatches.

Answer 5

1. Set up the equipment
2. Mark at least 5 straight lines across the surface at equal distance apart.
3. Place 300g of mass onto the trolley and add 100g of mass onto the hook and hold the trolley to the start line.
4. Start the stopwatch and you release the trolley and press “lap” as it passes each line on the surface.
5. Record the times at each distance for the applied force of 1N in a table.
6. Take 100g mass off the trolley and add it to the hook. Then measure the time taken for each segment again.
7. Repeat step 4 and 5 until all mass is on the hook and there is none left on the trolley.
8. Calculate the acceleration of your trolley.

Question 6

Write a method for a practical calculating the wave speed through a liquid. (ripple tank)

Answer 6

1. Set up ripple tank.
2. Count the number of waves that pass a given point every 10 seconds and record the results.
3. Measure the length of 10 waves and record results.
4. Change the frequency and take the measurements again.
5. Repeat until you have at least 6 sets of results. Then find the wave frequency and wavelength for each set of results.
6. Calculate the speed of the waves for each set of results using the equation:
   wave speed = frequency x wavelength

Question 6

Write a method for a practical calculating the wave speed through a solid.

Answer 6

1. Set up the equipment.
2. Put on eye protection and turn on the vibration generator. The attached string will begin to vibrate up and down.
3. If you cannot see a stable wave pattern along the string, adjust the length of the string. If you cannot see any waves at all, add another mass to the hanger and try moving the wooden bridge again.
4. Measure the length of one wavelength
5. Record the frequency of the signal generator.
6. Calculate the speed of the wave using the equation : wave speed : wave speed x frequency
7. Change the frequency on the signal generator and repeat steps 3-6 twice more.

Question 7

Write a method for a practical for the refraction of light by different substances.

Answer 7

1. Draw around a glass box and angle the ray box so the ray of light enters and exits on the long sides of the box.
2. Draw at least two crosses along the path of the ray entering the block and exiting.
3. Without moving the block, carefully draw two normals using a dashed line. These should be perpendicular to the edge of the block at the points where the ray enters and leaves the block.
4. Remove the block and draw straight lines with a pencil connecting the crosses for the rays exiting and entering the block.
5. Use a ruler to connect two lines showing the path of light through the block and arrow to show the direction of light.
6. Use a protractor to measure the angles of incidence and angles of refraction.
7. Record results in a table
8. Repeat all steps using a different material for the block

Question 8

Write a method for a practical investigating the reflection of light by different types of surfaces

Answer 8

1. Draw around a glass block and angle the ray box so that the ray of light hits one long side of the block and is reflected.
2. Draw two crosses along the path of the ray hitting the block and also for the ray reflected by the block.
   3 . Draw a normal using a dashed line. This should be perpendicular to the edge of the block at the point where the block meets the block.
3. Remove the block and draw straight lines with a pencil and ruler to join up the crosses for the lines hitting and being reflected by the block.
4. Add arrows to the lines to show the direction of the light
5. Using a protractor, measure the angle of incidence and reflection and record results.
6. Repeat all steps using a different material for the block.

Question 9

Write a method for a practical investigating the amount of infrared radiated from different surfaces

Answer 9

1. Place Leslie cube on a heat proof mat.
2. Boil kettle and fill the cube with the boiled water and replace the lid of the cube.
3. DO NOT TOUCH THE CUBE
4. Place infrared detector 5cm from the surface and measure infrared radiation radiated from each surface.
5. Measure the temperature using the thermometer and record results.
6. Measure the amount of radiation emitted by the other surface types. You should work as quickly as possible so that the temperature is the same for each measurement.

Question 10

Write a method for a practical investigating the amount of infrared radiation absorbed by different surfaces

Answer 10

1. Measure 10 cm of cold water using the measuring cylinder and pour into the black test tube.
2. Repeat step 1 for the white test tube.
3. Place the bulb 5-10 cm away from the test tubes and switch it on.
4. Take the temperature of the water using a thermometer and start the stopwatch.
5. After 2 minutes, retake the temperature of the water and record this in a results table. Repeat this every 2 minutes for 10 minutes.